tree 4f703687be0330fae7e7789f0a4534973535fd0a
parent f1569ff1d5ae0ca8598956be632947a88f540e2a
author Bart Van Assche <bvanassche@acm.org> 1414676711 +0100
committer Christoph Hellwig <hch@lst.de> 1415787369 +0100

blk-mq: add blk_mq_unique_tag()

The queuecommand() callback functions in SCSI low-level drivers
need to know which hardware context has been selected by the
block layer. Since this information is not available in the
request structure, and since passing the hctx pointer directly to
the queuecommand callback function would require modification of
all SCSI LLDs, add a function to the block layer that allows to
query the hardware context index.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>